1. Field of the Invention
This invention relates to a graft copolymer comprising a hydrocarbon polymer as a main chain to which a side chain composed of a styrene compound of the formula (I) ##SPC2##
wherein R is a hydrogen atom or an R'CO group in which R' is a hydrocarbon group having 1 to 20 carbon atoms and a polyene compound is grafted; and to a process for preparing the graft copolymer.
2. Description of the Prior Art
It is well known that hydrocarbon polymers having styrene compounds of the formula (I) grafted thereto have a wide range of utility as a result of their improved adhesiveness, dyeability and reactivity with other compounds which characteristics are inherent defects in the hydrocarbon polymers. However, it is desired to improve their mechanical and chemical properties further.
On the other hand, it has previously been known to use polyhydroxystyrene as an ion-exchange membrane. However, membranes of polyhydroxystyrene have the defect of inferior mechanical strength. With a view to increasing the mechanical strength of polyhydroxystyrene ion-exchange membranes, Japanese Patent Publication No. 26955/72 discloses a method for producing cationic exchange membranes from poly(p-hydroxystyrene) in which an inert polymer such as polyvinyl cloride is used conjointly, and poly(p-hydroxystyrene) is used in a partialy chlorinated state. The partial chlorination of poly(p-hydroxystyrene) is not desirable because partial chlorination complicates the process of producing ion-exchange membranes, and results in an increased cost of production and in a decreased number of reactive sites into which various functional groups can be introduced which is a characteristic of polyhydroxystyrene.